The principle of net neutrality means that Internet service providers (ISPs) must treat all internet communications equally, i.e. they may not discriminate or give advantage to any particular content by imposing economic barriers (e.g. by charging money for specific content) or structural obstacles by blocking or slowing down. This means that a level playing field must be guaranteed for users and content providers and ISPs must be prevented from unilaterally deciding on the availability of online contents. This is the reason why net neutrality is essential for an open democratic dialogue, in particular during the crucial period of elections. Some countries, though, have chosen to pursue the goals of free, open, universal internet access by other regulatory strategies.